(FILES) A guest takes a picture of the European Organisation for Nuclear Research (CERN) logo during an official ceremony marking the 60th anniversary of CERN in Meyrin near Geneva on September 29, 2014. The CERN physics laboratory chief welcomed China hitting pause on its major particle accelerator project, calling it an "opportunity" to ensure Europe's rival plan goes ahead. Ten years ago, China announced its intention to build the Circular Electron Positron Collider (CEPC), which would be the world's largest particle accelerator at 100 kilometres (62 miles) long. But Beijing recently put the project on ice, CERN's director-general Fabiola Gianotti told a small group of journalists in a recent briefing. (Photo by Fabrice COFFRINI / AFP via Getty Images)